Looking for advice on my 1996 Isuzu trooper. Replaced the engine about a year ago and motor has approx. 100K on it. Engine code led me to have the two cat units replaced. Had worked well until the two cat units were replaced. Used after market cats to save money. Since that the truck seems sluggish, loss of power, and very poor gas mileage. Engine idles fine. Replaced the fuel filter and cleaned the mass air flow sensor today and didn't make any change. Wondering what I should be the next step in troubleshooting this.

 

Your anti-lock braking system is on the fritz.You need to take it to the dealer, or a brake shop,and have them plug into your OBD computer andthey can diagnose the problem.